Antisecretory and serum gastrin lowering effect of enprostil in patients with duodenal ulcer disease.

This study was designed to compare the effects of enprostil, a synthetic dehydro-prostaglandin E2, on 24-h intragastric pH and serum gastrin profile in patients with duodenal ulcer disease. The dosing regimen included 3 enprostil groups: 35 microgram h.s. (at bedtime), 70 micrograms h.s., and 35 micrograms b.i.d., compared with cimetidine 600 mg b.i.d., and with placebo. Ten patients with inactive duodenal ulcer disease were randomly assigned to all five treatment regimens for 1 wk each according to a Latin Square design. There was a 1-wk washout period between each treatment. Intragastric pH and serum gastrin measurements were carried out on the last day of each treatment week. In placebo-treated patients, intragastric pH rose after each meal and fluctuated between 1.5 and 3.5. Enprostil 35 micrograms b.i.d. and cimetidine elevated pH after breakfast and during the night (p less than 0.05). The single nighttime dose of enprostil had a marked effect on pH only when given in the dose of 70 micrograms and this effect lasted over 13.5 h. The pH values during the night were similar in the groups treated with enprostil 35 micrograms b.i.d. and 70 micrograms h.s. During the daytime, the readings at or above pH 4 were placebo, 5%; cimetidine, 21%; enprostil 35 micrograms b.i.d., 34%. During the nighttime, the readings greater than or equal to 4 were placebo, 12%; cimetidine, 29%; enprostil 35 micrograms b.i.d., 39%; 35 micrograms h.s., 19%, and 70 micrograms h.s., 38%. The postprandial rise in serum gastrin was greatly enhanced by cimetidine, but the change after breakfast was dramatically blunted by enprostil 35 micrograms b.i.d. Gastrin concentration was increased with cimetidine during the night but there was no difference in gastrin concentration overnight between all regimens of enprostil and placebo. This study suggests that (a) enprostil 35 micrograms b.i.d. is as effective as cimetidine 600 mg b.i.d. in suppressing postprandial and nocturnal intragastric acidity; (b) enprostil 35 micrograms b.i.d. and 70 micrograms at night are similarly potent in suppressing nocturnal acidity; and (c) in addition to its cytoprotective effect, enprostil has potent antisecretory and antigastrin properties.